A Maltese businessman has been arrested as part of the investigation into the murder of journalist Daphne Caruana Galizia two years ago.
Yorgen Fenech was detained by armed officers after his yacht was intercepted and searched.
It comes a day after PM Joseph Muscat said he would consider a pardon for the alleged middleman in the case.
Caruana Galizia, an anti-corruption blogger, was killed by a car bomb near her home in October 2017.
Malta's handling of the case has drawn international criticism.
Mr Muscat referred to Mr Fenech as "a person of interest" in the case when addressing local media. A government source later confirmed to the BBC that Mr Fenech was arrested in connection with the ongoing investigation.
"The fact that the country's institutions were given the resources to carry out this operation – a major operation, to ensure no-one fled the country or tried to flee the country – shows the government's resolve and mine," the prime minister said. "We are leaving no stone unturned."
Witnesses quoted by the Times of Malta said Mr Fenech's luxury yacht was intercepted by an armed patrol boat as it left the port of Portomaso, north of Valletta, early on Wednesday.
On Tuesday, Mr Muscat said the alleged money launderer suspected of being the middleman would first have to give evidence in court before a pardon could be issued.
"I gave a mandate to the attorney general to negotiate with the person's lawyers to take an unprecedented step," the prime minister was quoted as saying.
"If the person collaborates and the information provided is sufficient to prosecute the mastermind of this crime, they will receive a presidential pardon."
Who is Yorgen Fenech?
Mr Fenech heads the Tumas Group and is a director of energy generating company Electrogas.
He has also been identified by Malta's Financial Intelligence Analysis Unit (FIAU) as being the owner of a Dubai-registered company called 17 Black.
In June the Council of Europe named 17 Black in a resolution outlining "fundamental weaknesses" that had allowed major scandals to go unchecked in Malta.
Its report said 17 Black had been expected to make large monthly payments to secret Panama companies owned by senior Maltese officials and had also received large sums of money from an Azerbaijani national.
Who else has been arrested?
As well as the suspected middleman – who has not been named – three other suspects are in custody over the journalist's murder.
Three men – brothers Alfred and George Degiorgio and their friend Vincent Muscat, all in their 50s – have been charged with triggering the car bomb which killed Caruana Galizia near her home in October 2017. They were arrested in December 2017 and pRead More – Source