Speedboat killer Jack Shepherd may fight the extradition process, his lawyer has confirmed, despite handing himself in to police in Georgia.

The 31-year-old surrendered at a police station in the capital, Tbilisi, on Wednesday – six months after he was convicted of killing 24-year-old Charlotte Brown during a speedboat date on the River Thames in London.

The web designer was found guilty of manslaughter by gross negligence and sentenced to six years in prison in his absence, although he was controversially granted leave to appeal in December.

Speaking to the Press Association, Shepherd’s Georgian lawyer, Tariel Kakabadze, confirmed that the process to extradite him back to the UK may be contested.

He said: “We just need to study the case documents and I need to discuss it with my client before making the final decision about it.

“As a lawyer I have to agree each step with my client.

Jack Shepherd talks to journalists as he hands himself in at a police station in Georgia’s capital, Tbilisi (Rustavi2/AP)

“If the extradition happens, it is important to make sure there will not be a danger to him in the UK.

“If I get assurances that his extradition is not dangerous, we might not disagree with extradition. Each step will be decided after we carefully study all the possibilities and options.”

On Wednesday night, the Crown Prosecution Service was preparing an extradition request to be lodged with Georgian legal authorities.

Shepherd is expected to appear for a short hearing at Tbilisi City Court on Friday.

Mr Kakabadze said the prosecutor will demand Shepherd’s arrest before the extradition – and that his arrest has to be confirmed by a judge according to Georgian law.

But he has also suggested it may be “some time” before Shepherd possibly returns to the UK.

Ms Brown’s family said they were overwhelmed with emotion after it emerged that he had surrendered, and her father said it was time for him to “atone” for his actions.

Jack Shepherd caseCharlotte Brown’s father Graham Brown (left) sister Katie (2nd left) and mother Roz Wickens (right) (Yui Mok/PA)

Home Secretary Sajid Javid said it is “vital Charlotte Brown’s family see justice done” and UK law enforcement will “seek to swiftly extradite him to Britain”.

And Theresa May’s official spokesman said: “The Prime Minister called earlier this month for Jack Shepherd to hand himself in to face justice and she welcomes the news that he is now in custody.

“It’s now essential that the judicial process is completed in the UK as soon as possible. The Government will now work alongside the police and the Crown Prosecution Service to ensure that extradition proceedings are expedited.”

Scotland Yard, the force leading the investigation, said officers had been updated by the National Crime Agency on the development and are awaiting confirmation of Shepherd’s identity.

The Metropolitan Police added that, once identity was secured, extradition proceedings “will begin immediately” against Shepherd, originally from Exeter, who was the subject of an international arrest warrant.

Under Georgian law, prosecutors are required to apply for restriction measures for a person wanted in another country within 48 hours of them being arrested.

On Wednesday, a heavily-bearded Shepherd – wearing a long coat, jeans and a check scarf – smiled as he walked into the station from a black car while flanked by lawyers.

In the footage shown on Georgian television station Rustavi2, he vowed to local reporters that he would clear his name over the “tragic accident”.

Speaking to journalists, he said: “Yes, my name is Jack Shepherd. I was involved in a tragic accident … in which a lady called Charlotte Brown tragically died.”

Billed by the network as an “exclusive interview”, Shepherd added that he hoped “justice will be done” with his pending appeal against the conviction.

Ms Brown, from Clacton-on-Sea, Essex, died in December 2015 when Shepherd’s boat flipped into the wintry waters of the Thames after they shared a Champagne-fuelled first date.

Her family ramped up pressure in recent weeks and renewed their calls for Shepherd to surrender after they met the Home Secretary on Tuesday.

Appearing on BBC Breakfast on Thursday morning, Ms Brown’s sister Katie said that, when the family heard Shepherd had handed himself in, they were all “very shocked and relieved”.

But she said that seeing him “stroll into the police station smiling and waving, it was unbelievable – his arrogance and everything”.

Jack Shepherd caseCharlotte Brown was killed during a speedboat date on the River Thames with Jack Shepherd (Metropolitan Police/PA)

Asked how she felt about the comments Shepherd made to reporters in Georgia, where he said he was frightened about what might happen and how he hoped justice will prevail, she said: “He seems to be concerned about his own feelings and how he’s felt throughout the whole thing, and has had no empathy or remorse for his reckless actions.

“He has caused the loss of my sister’s life and, whilst he’s been off in Georgia, he claims that he went to see friends and he has always wanted to see the scenery there – almost like he was claiming it was a holiday.

“He said that he has been out socialising, going to nightclubs, so, whilst he has been doing that, we have been back here, had the agony of the trial, left to pick up the pieces.

“He is not thinking about Charli, us, respect for the legal system, all he is thinking about is himself and his feelings.”

While Shepherd was on the run, his lawyers have been working to appeal against the conviction.

Shepherd’s UK solicitor, Richard Egan, said: “In the light of today’s developments I don’t think it would be appropriate to comment further until Mr Shepherd is back in the jurisdiction.”