Jennifer Hudson was living in fear of what her estranged fiance would do to her after accusing her of cheating on him, according to new court documents.

The Oscar winner has ended her 10-year romance with wrestler David Otunga and filed for a restraining order against him.

In new documents, obtained by TMZ, she has accused her ex of "aggressive, threatening and harassing behavior" towards her, adding, "I am now living in fear of further action David might take."

Jennifer claims the drama came to a head while she was recording new music in Chicago, Illinois with the couple's son.

When her fiance couldn't reach her, he allegedly asked David Jr. to record his mother, claiming he wanted evidence she was dating one of her producers, Mali Music. Jennifer has denied reports of a romance with the hitmaker.

Hudson states Otunga was "visibly angry" when she got home and alleges he became physical with her in front of a make-up artist and an assistant.

She also claims her fiance left a gun in clear view - an action she insists was intended to scare and intimidate her.

Hudson's mother Darnell Donaldson, brother Jason and seven-year-old nephew Julian King were murdered by her sister's estranged husband William Balfour in 2008.

"David knows that I am and have been very sensitive to firearms after my mother and my brother were murdered by a firearm," she writes. "I believe that he left it out to taunt, intimidate and frighten me, which he absolutely accomplished."

Reports suggest Jennifer and David split months ago. Both former lovers are seeking primary physical custody of their son.

Otunga, who has been ordered to stay away from his ex and their son, has issued a statement denying the singer and actress' claims, insisting she is simply attempting to gain an advantage in their custody dispute.

He has pulled out of the WWE Survivor Series coverage on Sunday (17Nov17).

Otunga was billed as one of the stars of the pay-per-view event, but sources close to the wrestler and TV personality tell TMZ he wants to focus on his child custody fight.

His lawyer tells the news outlet he "denies each and every allegation" Hudson has made against him.