In connection with the case, it also carried out raids at 5 locations in Delhi-NCR.
According to the agency, Devendra Sharma is being questioned and having his statement recorded in accordance with the Prevention of Money Laundering Act (PMLA).
Officials said that after his home was searched, he was taken to the ED office in central Delhi for questioning.
In a tweet, Sisodia asserted that the investigation agencies had brought a "false" case against him and that the ED had searched his PA's home and "arrested" him.
"After lodging false FIR, they raided my house, searched bank lockers, and checked in my village but found nothing against me. Today, ED conducted a raid at my PA's house. When ED did not find anything there either, they arrested him and took him away. BJP people! So much fear of losing the election..," Sisodia tweeted in Hindi.
In this case, the ED has already carried out a number of raids. It detained Sameer Mahandru, the managing director of the liquor-making business Indospirit, in September.
The money laundering case began with a CBI FIR in which Sisodia was among the accused.
After filing the case, the CBI conducted a raid on the deputy chief minister's and some bureaucrats' homes in Delhi.
The Delhi LG recommended a CBI investigation into alleged irregularities in the execution of Delhi's Excise Policy 2021–2022, which brought the excise scheme under scrutiny. 11 excise officials had also been suspended by the LG.
(With inputs from PTI)