Philippine President Rodrigo Duterte on Saturday fired two immigration officials facing allegations of corruption as he reaffirmed his commitment to ensure a clean government, informs Reuters.

Just shortly before Duterte arrived in his hometown Davao City from Singapore, local media reported that two immigration officials accused of extorting 50 million pesos ($1 million) from Jack Lam, a Chinese citizen and head of Hong Kong-listed Jimei International, had tendered their resignation.

The two officials, however, had denied the allegation and said they were a target of a demolition job for investigating corruption in the immigration bureau, the reports said.

Lam, from the Chinese gambling enclave of Macau, faces allegations of economic sabotage and bribery in the Philippines.

Lam's whereabouts are unknown. His lawyer in the Philippines has previously denied the accusations against Lam.

Last month, local immigration authorities detained about 1,200 Chinese men accused of working without permits at Lam's online gambling operation in Clark Field, a former U.S. air force base in the Philippines.

An associate of Lam had tried to secure their release, according to the country's police chief Ronald Dela Rosa, who also said Lam had left the Philippines but was willing to return and assist in any investigations.

Duterte has also ordered the seizure of Lam's assets in the Philippines after he accused him of not paying the correct taxes.