The Solicitors Regulation Authority (SRA) said it had shut down Rashid & Rashid in South Wimbledon, Kingswright Solicitors in Birmingham and Lincoln Lawrence in Hounslow following the undercover operation by the Daily Mail.
The newspaper reported that numerous solicitors agreed to help an undercover reporter posing as an economic migrant to submit a false asylum application in exchange for thousands of pounds.
The SRA is an independent regulatory body for solicitors in England and Wales. Its rules prevent lawyers from misleading courts, and acting dishonestly or with a lack of integrity could see someone struck off.
In a statement, the SRA said: "We have closed down three solicitor firms that were named in a Daily Mail undercover operation involving immigration services.
"These firms are Rashid & Rashid in South Wimbledon, Kingswright Solicitors Birmingham, and Lincoln Lawrence in Hounslow."
The watchdog said its intervention meant it had stopped the firms from operating, had taken possession of all documents and papers held by the companies and had seized all money in its possession, including clients' money.
The practising certificates of the following solicitors have been automatically suspended so they cannot practice as a solicitor, the regulator added.
The SRA said its "interventions can be challenged at the High Court" but "if that challenge is not successful, intervened firms remain closed, they do not re-open".
Sky News approached the three law firms in question but did not receive a response to requests for comment.
The SRA's intervention was welcomed by Home Secretary Suella Braverman who tweeted: "Immigration lawyers who cheat and lie are taking the British public for a ride. Good to see this quick action by the SRA."
Immigration minister Robert Jenrick echoed her words, saying: "Immigration lawyers who cheat the system must be struck off. Good to see the first of what needs to be many more actions by @sra_solicitors."
The SRA investigation was launched after the government wrote to the watchdog to say the "full force of sanctions" should be employed in the wake of the Daily Mail investigation.
Justice Secretary Alex Chalk also called for a follow-up to the review the body carried out on immigration advice last year - highlighting the importance of "ensuring public confidence in our immigration system".
The SRA's immigration and asylum thematic review found the overall quality was satisfactory and there were no widespread or systemic failings or issues with quality. By Alexandra Rogers, Sky News
