Washington (CNN) Special counsel Robert Mueller's office said Friday that former Trump campaign official Rick Gates is still helping "several ongoing investigations" and isn't ready to be sentenced.

"Gates continues to cooperate with respect to several ongoing investigations, and accordingly the parties do not believe it is appropriate to commence the sentencing process at this time," the filing said, pointing out that the situation had not changed since the previous update in January.

There was heavy speculation that Gates' cooperation would wind down this week, given the conclusion of the federal cases against his longtime partner Paul Manafort. Gates was a star witness in that case and testified against Manafort, who was sentenced by two judges to serve a total of 7.5 years in prison for financial fraud.

The filing suggests that Gates might still be helpful beyond Manafort, and that there are investigators who still want Gates' cooperation. Whether it's Mueller or prosecutors in the Southern District of New York, or perhaps elsewhere, is not entirely clear. If Gates wasn't needed anymore, the parties likely would have asked to set a sentencing date.

The filing comes amid signs that Mueller is wrapping up his work and will deliver his final report to Attorney General William Barr concerning his probe of Russian meddling in the 2016 presidential election. That report could be completed even if investigations continue elsewhere, including in the Southern District of New York.

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