Linda Box, 66, has had her practising certificate suspended by standards monitor the Solicitors Regulation Authority (SRA) after it intervened to force Wakefield-firm Dixon, Coles and Gill to officially close down.
The firm, which had offices in Wakefield and Horbury, shut its doors in January after more than 200 years of practising law after a fraud investigation was launched by police.
But the SRA has now stepped in to formally prevent the firm from operating.
The board said it had “reason to suspect” dishonesty on the part of Box and suspended her from practising as a solicitor.
An SRA spokesman said: “The practising certificate of Linda Box has been automatically suspended so she cannot practice as a solicitor.
“The practising certificates of Julia Wilding and Julian Sanderson [also partners in the practice] have not been suspended.
“An intervention means the SRA has closed the firm with immediate effect.
“It will stop the firm from operating, take possession of all documents and papers held by the firm and take possession of all money held by the firm.”
The 200-year-old practice closed on January 29 and a fraud investigation was launched by police.
A police spokesman said: “West Yorkshire Police are investigating allegations of fraud against a solicitors firm in Wakefield.
“A 66-year-old woman has been arrested in connection with the investigation and has been released on police bail. Enquiries are ongoing.”
The SRA said the firm announced its closure in January without intervention from the regulatory body and was in the process of shutting down.
But it said it had now stepped in to immediately complete the closure and take control of ongoing client matters.
A spokesman said: “We will only get involved if there is a risk to clients and the public interest.”
The regulatory body said it would now complete its investigation and decide on appropriate action.
But it said it would not disclose any further details of the investigation unless disciplinary proceedings become necessary.
The Yorkshire Post understands the firm had around 7,000 customers prior to its closure..
A voice message on the company’s phone prior to its closure said: “The legal practice of Dixon Coles and Gill closed its doors for the last time on Friday 29 January after providing legal services to the people of Wakefield and beyond for more than 200 years.
“However the members of the firm remain available and keen to welcome their existing clients to their new practices.”