The Enforcement Directorate on Wednesday arrested Aam Aadmi Party Rajya Sabha member Sanjay Singh in connection with the Delhi excise policy case, officials said.
This comes after the agency conducted searches at his residence earlier in the day in connection with the case.
The officials said premises belonging to some others connected to the case were also covered during the operation.
The ED had earlier questioned the members of staff and those linked to the 51-year-old Rajya Sabha MP.
It is alleged that the Delhi government's excise policy for 2021-22 to grant licences to liquor traders allowed cartelisation and favoured certain dealers who had allegedly paid bribes for it, a charge strongly refuted by the AAP.
The policy was subsequently scrapped and the Delhi lieutenant governor recommended a CBI probe, following which the ED registered a case under the PMLA.