Thailand murders: Police 'close to making an arrest'
Thai police investigating the murders of two British tourists say they are "close to making an arrest".
Hannah Witheridge, 23, and David Miller, 24, were found dead on the island of Koh Tao on 15 September.
The BBC's Jonathan Head said police are now trying to find a man who left the island that day and is thought to be hiding in the Thai capital Bangkok.
Police believe "all persons of interest" in the case have been identified, he added.
Two murder weapons
At least three men are thought to have been involved in the attack on the Britons, whose bodies were found on a beach, close to the bungalows where they had been staying.
According to post-mortem examinations, Ms Witheridge, from Great Yarmouth, Norfolk, died from head wounds while Mr Miller, from Jersey, was killed by severe blows to the head and drowning.
Two items - a heavy garden hoe and a piece of wood - have been identified as the murder weapons.
Analysis: Jonathan Head, BBC south-east Asia correspondent
Late last week, the Thai police admitted their investigation into the murders on Koh Tao would have to start again. Senior national police officers arrived to demonstrate their renewed seriousness.
Local people had repeatedly said they believed there was a connection with the AC Bar, which David Miller and Hannah Witheridge visited before they were killed and where they reportedly got into an argument with some local men. But it was only on Tuesday this week that police first questioned the AC Bar's owner and his brother.
The police are now sounding more optimistic, saying they have now identified all "persons of interest" in the case, and that they believe they will be able to make an arrest soon.
However we have heard mixed messages from the police in the past.
They still need to find the possible suspect in Bangkok, and they need to match his - and any other possible suspects' - DNA against that of the victims. Only then will we know they are close to solving this crime.
More than 100 officers are involved in the investigation and they have been collecting evidence and taking DNA samples from those working on the island.
Our correspondent said attention had focused on one of the most powerful families on the island.
Police have now questioned the owner of the bar where Mr Miller and Ms Witheridge were reported to have been involved in an argument shortly before they were killed, he said.
He added: "His brother has been identified as a man seen running on CCTV pictures taken near the crime scene - he was also questioned for three hours.
"Both men gave DNA samples, but have not been charged. The police say they are now searching for another man connected to the family who fled to Bangkok shortly after the crime."
Police had previously said they suspected two different samples of DNA taken from Ms Witheridge's body were from two Asian men.
A reward of about £4,000 has been offered for information leading to arrests.