Germany's top criminal court has thrown out the conviction of former arms-industry lobbyist Karlheinz Schreiber, ordering a retrial after saying errors were made in the 2010 process.

The 77-year-old German-Canadian was found guilty last year of tax evasion for failing to report some 14.6 million Deutsche marks, or about $10-million, in income.

Among other things, the Federal Criminal Court in Karlsruhe said in its ruling Tuesday that the Augsburg state court incorrectly rejected Mr. Schreiber's request to consider evidence of Canadian residency for tax purposes.

It was not clear when the retrial would take place.

Mr. Schreiber was arrested in Canada in 1999 under a German warrant and sent to Germany last year after a 10-year battle against extradition.

Mr. Schrieber was extradited after an Ontario court denied his bid to stay in Canada and after public hearings into his controversial financial dealings with former prime minister Brian Mulroney ended.

The charges he faced in Germany stemmed from money he allegedly received from the sale of German armoured vehicles to Saudi Arabia in 1991. Mr. Schreiber has denied the charges.

Mr. Schreiber was also alleged to have given a cash donation in 1991 to the former treasurer of chancellor Helmut Kohl's Christian Democratic Union, Walther Leisler Kiep. The scandal deepened with Mr. Kohl's admission in 1999 that he had accepted illegal donations from supporters.

Prosecutors, however, closed their case against Mr. Kohl without charging him after he agreed to pay a substantial fine.

During the public hearings in Ottawa, Mr. Mulroney admitted accepting $225,000 in cash from Mr. Schreiber, but insisted he broke no laws or ethical guidelines.

He said the payment was for his services in trying to line up support from political leaders in Russia, China and France for the proposed purchase of vehicles for United Nations peacekeeping work.

Mr. Schreiber claimed the payments totalled $300,000, not the $225,000 Mr. Mulroney declared for tax purposes.

He also maintained that Mr. Mulroney was supposed to lobby Canadian officials, not foreign leaders.

With files from The Canadian Press