Anti-corruption agents have raided and removed papers from the house of Malawi's ex-president, Bakili Muluzi.
Bingu wa Mutharika (back) has fallen out with his predecessor Bakili Muluzi (front)
A court search warrant was obtained despite a ruling that he did not have to undergo questioning about his financial dealings with donors.
Hundreds of Mr Muluzi's supporters gathered outside during the search chanting angry anti-government slogans.
They say President Bingu wa Mutharika is mounting a witch-hunt against his predecessor, after the two fell out.
Mr Mutharika, who was handpicked by Mr Muluzi to run as the United Democratic Front candidate in the 2004 presidential elections, resigned from the UDF earlier this year because of the unpopularity of his anti-corruption campaign.
David Kanyenda, Mr Muluzi's lawyer, said that the former president had been at home in Blantyre when the seven police officers and seven Anti-Corruption Bureau agents arrived at 0900 local time.
Mr Muluzi had co-operated fully with the agents, who left after five hours, he said.
He described the raid as political harassment because the High Court had granted an injunction that Mr Muluzi did not have to appear before the Anti-Corruption Bureau hearing on Monday.
He had been summoned to testify to account for millions of dollars of aid money during his presidency between 1994 and 2004.
"You must understand that this is a campaign to intimidate and harrass the former state president," Mr Kanyenda told the BBC's Focus on Africa programme.
Other agents searched Mr Muluzi's house in his home village of Kapoloma, 120km north east of Blantyre.
The private residence of his son, MP Atupele Muluzi, was also searched.
The BBC's Raphael Tenthani, reporting from the scene, said about 50 heavily armed police officers were trying to keep at bay some 300 pro-Muluzi supporters.
They had gathered to vent their anger at Mr Mutharika, who they feel is ungrateful to the party that sponsored his election victory last year.
"As a party, we're angry and annoyed because we know this is a political move," Kennedy Makwangwala, the UDF's secretary general said.
Mr Muluzi's UDF is at the forefront of the bid to impeach Mr Mutharika, who was elected on a UDF ticket.
On Tuesday, supporters of the president, angry at moves to impeach him, attacked opposition MPs outside parliament.
Impeachment proceedings have been temporarily halted as a constitutional court considers procedural rules.