Israel's attorney-general has ordered police to open a criminal investigation in two unspecified matters involving Prime Minister Benjamin Netanyahu, Israel's Channel 10 television said on Wednesday.

When asked, a Justice Ministry spokeswoman declined to respond to the report.

Netanyahu has in the past denied wrongdoing in the purchase of submarines from Germany, where media have reported a potential conflict of interest involving his lawyer.

The Channel 10 report said one of the two cases that Attorney-General Avihai Mandelblit had been examining was not known to the public.