The registration of the case comes ahead of the Maharashtra Assembly polls.
Workers of the NCP's youth wing staged a protest outside the Enforcement Directorate's (ED) office in Mumbai today to condemn the registration of a money laundering case against party chief Sharad Pawar and others in connection with the MSCB Bank scam.
Five party activists were later detained, police said.
The protesters, led by NCP youth wing's state unit chief Mehboob Shaikh, gathered outside the ED office here and shouted slogans against the ruling BJP and the government.
Mr Shaikh said the protesting party members were baton charged by police and later detained.
"The ED filed the case against Pawar given the huge response his campaign rallies have received. The ED is being used to stifle voices of the opposition leaders ahead of the election. Hence, we staged the protest outside the ED office to condemn the action," he said.
Five NCP activists were detained and taken to Mata Ramabai Ambedkar Marg police station, a police official said.
"Since the protesters were reluctant to go, the police had to use force in an attempt to disperse them," he said.
The ED has filed a money laundering case against Sharad Pawar, his nephew Ajit Pawar and others in connection with the Maharashtra State Cooperative Bank (MSCB) scam case, the officials said on Tuesday.
An Enforcement Case Information Report (ECIR), equivalent to a police FIR, has been registered by the central agency under the Prevention of Money Laundering Act, they said.
The case is based on a Mumbai Police FIR which had named former chairmen of the bank, ex-deputy chief minister of Maharashtra Ajit Pawar and 70 former functionaries of the cooperative bank.
The registration of the case comes ahead of the Maharashtra Assembly polls scheduled to be held on October 21.