An arrest warrant has been issued for Liberia's former finance minister following allegations he was involved in a $500m (£389m) corruption scam.

Samuel Tweh, along with four other senior officials in former President George Weah's administration, have been indicted for allegedly stealing from the government when they were in office.

Mr Tweh, who was previously sanctioned by the US for corruption, called the indictment a "politically motivated witch-hunt" against him and other former officials.

The Weah adminstration, whose six years in power ended in January, was plagued with allegations of corruption and financial mismanagement.

When President Joseph Boakai took over, he pledged to crack down on corruption.

On Monday, the five former officials were indicted for economic sabotage, illegal disbursement and expenditure of public money, criminal conspiracy and other charges.

City Court in the capital, Monrovia, subsequently issued warrants for their arrest.

Three of the men - former national security adviser Jefferson Karmoh, state prosecutor Nyenati Tuan and accountancy boss at the Finance Intelligence Agency (FIA), Moses Cooper - were unable to pay bail and have therefore been detained in Liberia's central prison.

They or their legal representatives have not yet commented on the allegations.

Mr Tweh and former FIA chief Stanley Ford are yet to be arrested - the police are unsure of their exact whereabouts.

It is not the first time the ex-finance minister has been accused of corruption - last December the US sanctioned him and two senators for "abusing their public positions through soliciting, accepting and offering bribes".

Mr Tweh denied this allegation at the time and in response to Monday's indictment, he wrote on Facebook: "Today a politically motivated witch-hunt has been officially launched against my person, calling for my arrest.

"Over the last six years, I have been a major political target and have faced falsely devilish accusations."

Mr Boakai took office in January after defeating Mr Weah in a run-off election.

In his drive to tackle corruption, he declared his assets and ordered an audit of the presidential office. The results have not yet been released.

Mr Boakai has also beefed up the General Auditing Commission and the Anti-Corruption Commission.