New information and evidence of wrongdoings were piling up against Laxmipur MP Mohammad Shahid Islam, charged with human trafficking and money laundering in Kuwait, media reported.
Kuwaiti media have accused the MP of trading visas and siphoning off money to the US for laundering.
Sources close to the investigation told Kuwait's Al Qabas newspaper that the suspect is a member of a three-man racket whose other members include another Bangladeshi MP, whose wife is also an MP from the seats reserved for women.
It added that the trio occupied sensitive positions in three major companies that brought over 20,000 Bangladeshi workers into the country in exchange for large sums of money believed to be in excess of 50 million dinars ($163 million).
The MP reportedly channelled the money to the US to set up a company in partnership with an American national, according to the report.
Sources said that, the number of those under investigation in Kuwait had increased to nine. Four new officials, who are being interrogated by the Kuwaiti public prosecution, include two directors of the Public Manpower Authority, a colonel in the Ministry of Interior, and a businesswoman.
The number is expected to increase as the investigation progresses. There is new information and evidence for the prosecution, they added.
Shahid pleaded innocent after he was arrested by the Criminal Investigation Department in Kuwait on June 6, but he gradually confessed to the charges.
The nine were interrogated based on the information that he paid large sums of money to high-placed officials, including a security official, former and serving Kuwaiti lawmakers.
He told the investigators that certain Kuwaiti quarters within the government were involved in residency trade which paved the entry of Bangladeshi workers to the Arab country in exchange for money.
Shahid and a Kuwaiti citizen co-own a big recruitment company named Marafie Kuwaitia.
Bangladeshi witnesses had ealier given a rare glimpse of the grip of the Bangladeshi MP on his compatriot workers.
The witnesses said the MP was like a mafia boss who demanded 'taxes' from poor, low-income workers, who obeyed and paid payments to him, Al Rai reported.
"The accused's men were imposing a "royalty" on workers, at a value of 8 dinars per day," a witness said.
Shahid is held in custody pending trial.
During interrogation, Shahid reportedly confessed to have provided 1.1 million dinars ($3.58 million) by check to an official at the Ministry of Interior, one million dinars ($3.25 million) in cash to another official, in addition to "bags" of millions of dinars in cash to a third official, Kuwaiti media reported.