A judge on Tuesday postponed the sentencing of Pedro Hernandez for the murder of 6-year-old Etan Patz at least until April to give the defense time to prepare a motion challenging his Feb. 14 conviction on the basis of possible jury contamination.

Defense lawyers are pursuing reports in Newsday and elsewhere about one juror who said court officers at the monthslong retrial told the panel that members of a previous hung jury were attending. Members of the previous jury, which deadlocked for conviction 11-1 in 2015, sat with Etan’s father during the retrial.

Manhattan Supreme Court Judge Maxwell Wiley, who had ruled that the new jury wasn’t supposed to know about the earlier trial, said the defense should file motions to overturn the verdict next month and he would try to rule by April 4.

The “sanctity and integrity” of the jury process “wasn’t kept intact,” defense lawyer Josh Dubin told reporters after a brief hearing. “The concern is that the jurors were provided information they should not have had, and that’s the problem,” Dubin said.

Prosecutors wanted Hernandez to be sentenced Tuesday to end as early as possible an ordeal for the Patz family that began when Etan disappeared in 1979. They declined to comment afterward on the allegations of jury contamination, but Manhattan District Attorney Cyrus Vance Jr. commented briefly after a news conference on Monday.

“We really have to see the facts behind that,” Vance said. “ . . . Personally, I feel confident that the jury and the court managed this process well.”

Etan disappeared on his way to catch a school bus. Hernandez, 55, of Maple Shade, New Jersey, worked in a bodega in the boy’s SoHo neighborhood at the time, and said in a disputed confession that he lured Etan into the bodega’s basement and strangled him.