ABUJA, June 4 (Reuters) - Nigeria's government has recovered $9.1 billion in stolen money and assets, its information and culture minister said on Saturday, as its corruption crackdown continues against the backdrop of the country's worst economic crisis in years.

President Muhammadu Buhari, elected last year largely on his vow to fight corruption, has vowed to recover "mind-boggling" sums of money stolen from the oil sector and said public coffers were "virtually empty" when he took office last May.

Since then the country has endured an economic crisis caused by the sharp fall in global oil prices, making the need to recoup lost money more acute. Crude sales account for around 70 percent of national income.

In a statement, Information Minister Lai Mohammed said cash and assets recovered between May 29 last year, when Buhari took office, and May 25 this year totalled $9.1 billion.

The government has said it plans to generate 3.38 trillion naira ($17 billion) this year from non-oil sources to help fund the $30.6 billion budget signed into law by Buhari last month.

It was not immediately clear how much outstanding money in total is still being sought by the government.

"All these are monies recovered from individuals and entities who had either hidden, stolen, diverted or were in possession of monies belonging to the nation," the minister's special adviser, Segun Adeyemi, told Reuters.

"These recovered funds include monies withheld by past government officials, monies kept in private accounts, monies diverted to private pockets and monies in possession of government officials not disclosed after leaving government."

The information minister told Reuters he could not name any individuals from whom money had been recovered for legal reasons.

He said some of the money came after companies that had failed to pay taxes were forced to do so retrospectively.

The ministry also said a total of $321 million was yet to be recovered from Nigerians in Switzerland, the Britain, the United States and the United Arab Emirates or their assets held in those countries.

Last month Buhari urged other countries and the United Nations to speed up the process of repatriating stolen money held abroad, which he said was becoming "tedious." ($1 = 198.8000 naira)

(Reporting by Camillus Eboh and Felix Onuah; Writing by Alexis Akwagyiram; Editing by Alison Williams)