PRINCE Andrew has been spotted for the first time since his associate Ghislaine Maxwell was sentenced to 20 years in prison over sex trafficking offences.

The Duke was seen grinning while horse riding on Wednesday morning at Windsor Castle just hours after his former friend was convicted.

It comes amid reports the Queen’s grandson could be one of the FBI’s next targets for investigation.

Lawyers representing the victims of Jeffrey Epstein and Maxwell pleaded with US prosecutors to look into the pair’s associates.

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Maxwell had been sentenced on Tuesday to 20 years in prison for luring young girls to massage rooms for disgraced financier Epstein to molest.

The 60-year-old looked straight ahead and showed no emotion as a judge in the Southern District of New York passed sentence in front of a packed public gallery.

The British socialite’s accusers came face to face with her on Tuesday as several women read victim impact statements to the court – describing her as a “manipulative, cruel and merciless person.”

Maxwell, who was described as “dangerous” by the prosecution during her three-week trial last year, helped entice vulnerable teenagers to Epstein’s various properties for him to sexually abuse between 1994 and 2004.

She told her victims: “I am sorry for the pain”, adding “I hope my … incarceration brings you pleasure.”

Now, reports suggest Prince Andrew could soon find himself under investigation.

One lawyer reportedly said: “Obviously, Andrew is one target they will be looking into.”

The Duke has known Maxwell since she attended Oxford University. They remained friends and were connected through the same social circles.

In 1999, Prince Andrew even took the Maxwell and Epstein to Balmoral, the Queen’s estate in Scotland. Maxwell and Andrew also travelled to Epstein’s private Caribbean Island together on the financier’s private jet.

A year later, the pair reportedly travelled on a number of trips including New York, Florida, Thailand and London.

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In the same year, the Prince also hosted Maxwell and Epstein at the Queen’s Sandringham estate for what he described as a “straightforward shooting weekend”.

Earlier this year, the Duke of York and his accuser Virginia Giuffre reached an out-of-court settlement in a civil sex claim filed in the US, costing the Prince £12 million.

Andrew pledged to “demonstrate his regret for his association with Epstein” by supporting the “fight against the evils of sex trafficking, and by supporting its victims”.

The Duke has repeatedly denied the allegations made against him.