Seal Under Investigation for Sexual Battery

Seal is under criminal investigation for sexual battery, just one week after he publicly encouraged sexual abuse victims to come forward ... but the singer denies any wrongdoing.

Actress Tracey Birdsall tells us she and Seal were neighbors in Los Angeles in the fall of 2016. She says the two developed a close friendship -- and only that -- until an incident at Seal's home. Tracey says she was in Seal's kitchen to retrieve a salad spinner she'd lent him when all of a sudden, he lunged at her.

Tracey tells us Seal forced himself on her, attempting to kiss her. She says she shouted, "What are you doing?!" and the singer replied, "I'm kissing you!"

Birdsall claims Seal then began to belittle her for what she was wearing (a tank top and shorts) -- insinuating she was asking for it -- and he began to grope her breasts. She says she demanded he stop.

Tracey tells us Seal then invited her to sit on the couch next to him ... she says she was in shock and complied. Birdsall claims Seal once again began to make fun of what she was wearing and groped her again. Tracey says she left shortly after that and did not have contact with Seal again.

Birdsall says it wasn't until she saw Seal's comments about Oprah and Harvey Weinstein -- where he encouraged women to share their own stories of sexual misconduct -- that she decided to report it to the cops.

A source with the L.A. County Sheriff's Dept. confirms a report was taken Saturday for sexual battery ... the incident is under investigation.