Before stepping into the Crime Branch office in Dona Paula on the outskirts of Panaji, Monserrate said he was innocent and a victim of controversy.
"This is a set up. I am innocent and have nothing to fear. I am being targeted as part of a controversy," said Monserrate, who was accompanied by his wife and Congress MLA Jennifer.
On Wednesday, Monserrate, also known as Babush, was booked by Panaji police officials for allegedly raping a minor girl, who was earlier in his employ.
Police sources said Monserrate was formally arrested minutes after his surrender.
According to Superintendent of Police (Crime) Karthik Kashyap, the First Information report was filed under sections 342 (wrongful confinement), 328 (causing hurt), 370 (detaining against will), 376 (rape) and relevant sections of the Protection of Children from Sexual Offences Act and the Goa Children's Act.
"The FIR has been registered on the complaint of the victim, who is a minor girl, against a person called Babush and further investigation is going on. It is being undertaken by the women's police station. The investigation is at a preliminary stage," Kashyap said.
However, speaking to IANS, Monserrate said the complaint against him was a result of a political conspiracy.
"I had hired this girl to work in my Hallmark store because her parents came to me to look for a job. But she stole some money from the counter and I had sacked her. This complaint is false. There is no question of my getting intimate with her," Monserrate said.
"She has complained at someone else's bidding," Monseratte also said, without giving more details.
Monserrate was elected to the St. Cruz constituency on a Congress ticket, but was sacked from the party after he started hobnobbing with the Bharatiya Janata Party.
He has been booked in the past for extortion. His son Rohit was also arrested for allegedly raping a minor German girl five years ago, but was later acquitted.