Staff at Brooklyn’s Metropolitan Detention Center aren’t allowing quarantined inmates to contact their attorneys — just days after a judge put prosecutors on notice about the issue, defense lawyers claim.

Attorneys for the Federal Defenders of New York said in a Tuesday letter to Brooklyn federal Judge Margo Brodie that the organization was blocked from speaking with three of its clients because they were being held in medical isolation for having coronavirus symptoms.

Brodie had warned prosecutors appearing on behalf of the US Bureau of Prisons at an April 24 telephone hearing that “inmates are entitled to their legal calls and must be allowed to place their calls, even though they’re in medical isolation,” according to a transcript of the proceedings.

“Even if it’s an isolated incident, it should not be happening at all,” Brodie said to the prosecutors.

Sean Hecker, an attorney representing the Federal Defenders, said in a letter to Brodie that MDC does not have a policy of restricting inmate calls if they are being held in quarantine — and yet at least one call was cancelled on Monday because, a prison staffer said, an “inmate is in isolation.”

As of April 23, six inmates and 26 staff members at MDC had tested positive for coronavirus, according to a report to a federal judge — though union reps told The Post that number is an undercount due to a lack of widespread testing.

The Federal Defenders’ lawsuit was filed in January 2019 and originally addressed MDC’s move to cancel visitation by inmates’ and family members following a fire that partially knocked out power to the prison — plunging the 1,700-bed federal lockup into a “humanitarian crisis” as it struggled to keep the heat on, the organization charged.

The US Attorney’s office in Brooklyn declined to comment.