He said his office had on Saturday filed about 30 requests for legal assistance with Egyptian authorities to establish the origins of the funds.
Lauber said that under Swiss law "a direct link has to be established to complete our criminal cases" and return the assets.
Egypt's top appeals court last week upheld a three-year prison sentence for Mubarak and his two sons for corruption.
It was not clear, however, how long Mubarak would remain in detention. Both of his sons were set free in October with time served taken into account.
Mubarak has spent most of his time in a military hospital since his arrest in 2011, months after his ouster in a popular uprising.
In May, a court sentenced him and his sons to three years for having embezzled 125 million Egyptian pounds ($16 million) from funds meant for the maintenance of presidential palaces.
They were fined that same amount and an extra 21 million Egyptian pounds.