TBILISI -- Georgian prosecutors have accused former President Mikheil Saakashvili of authorizing a plot to kill an opposition politician who died in Britain in early 2008 -- a charge he immediately rejected.

The Prosecutor-General's Office announced on October 17 that it had concluded its investigation into Badri Patarkatsishvili's case, alleging that Saakashvili had "authorized" the Interior Ministry's Constitutional Security Department to organize the plot, which a statement said involved the then-head of the agency, Data Akhalaya, and three of its senior executives.

One of them, Giorgi Merabishvili, was detained a day earlier.

Patarkatsishvili, a businessman who became extensively involved in Georgian politics, unsuccessfully ran against Saakashvili in the January 2008 presidential election.

He died in his home in Britain the following month as a result of what British authorities described as a heart failure.

However, some politicians in Georgia have alleged Patarkatsishvili was assassinated.

Saakashvili, who was president of Georgia from 2004-13, rejected the prosecutors' accusations on Facebook, describing them as an attempt by the ruling Georgian Dream party to discredit his United National Movement ahead of Georgia’s October 28 presidential election

Saakashvili, who currently resides in the Netherlands, was sentenced in absentia to six years in prison in June after a court in Tbilisi found him guilty of abuse of power over the 2005 beating of Georgian lawmaker Valery Gelashvili.

And in January, he was sentenced in absentia to three years in prison after being convicted of trying to cover up evidence about the 2006 killing of Georgian banker Sandro Girgvliani.

He has rejected all the charges, calling them politically motivated.