The condition of Union Commerce Minister Murasoli Maran, undergoing treatment in a hospital in the United States, has suffered a "set back".

Stating this, Dr Akilan Ramnathan, additional private secretary to the Union minister of state for health and family welfare, said Maran's condition was being closely monitored by a team of doctors at the Methodist Hospital, Houston, Texas.

"Prime Minister A B Vajpayee is monitoring the treatment," Ramanathan said in a statement.

Maran was admitted to the Apollo Hospitals in Chennai on September 23 following high fever. He underwent a "high risk" surgery a couple of days later for replacement of infected mitral valve.

He subsequently developed various other complications and was put on dialysis.

The ailing DMK leader was flown on November 14 to the Methodist Hospital for treatment of heart, kidney and other vital organs.

In the first week of this month, a press release from the Union health ministry quoting US doctors said his condition had improved "significantly" with his heart functioning well and blood pressure normal.