Amanda Bynes Threatens to Sue NYPD Over Alleged Sexual Assault, Arrest

Actress Amanda Bynes, who was arrested last week on marijuana possession and other charges, has said she plans to sue the New York City Police Department and her family.

WATCH: Amanda Bynes Denies Downward Spiral

In a series of tweets on Sunday, Bynes again said she was not guilty of the charges against her, repeated her claim that the arresting officer entered her Manhattan apartment illegally, sexually harassed her and wrongfully arrested her.

"My lawyer and I are taking this mistake extremely seriously! You cannot illegally enter my apartment then take me to mental hospital without any grounds," she wrote. "I have never been so offended in my life. They found nothing criminal on me or around me, one cop then sexually assaulted me, so I'm suing for all of the above! I'll be happy when I get money compensation from the cop who assaulted me and NYPD for wrongfully arresting me and having me put into a mental hospital and jail overnight! I don't want to keep talking about it."

RELATED: Amanda Bynes: A Cop Sexually Harassed Me

The former child star, now 27, had tweeted earlier that the officer lied about the bong and that she opened the window "for fresh air." She also tweeted that the officer "slapped (her) vagina," and that she called police to report that alleged conduct.

She has also tweeted that she was sent to a mental hospital.

The NYPD is investigating the sexual allegation claim. A source familiar with the investigation told ABC News that the police interviewed the building manager, who was present during the entire encounter. The building manager said no one touched Bynes inappropriately at any time, the source said.

The source also said Bynes was already on the phone making allegations against the police even before they entered her apartment.

MORE: Amanda Bynes After Arraignment: 'I've Never Had a Bong in My Life!'

The "Hair Spray" actress was arrested Thursday night and charged with reckless endangerment, tampering with physical evidence and criminal possession of marijuana. Police who responded to a 911 call at her apartment building said they saw her throw a bong out of her apartment window.

In court, her lawyer, Andrew Friedman, said that Bynes did not heave a bong out of her window, and that police had no reason to enter her home.

Bynes was arraigned on the charges and released Friday morning.

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In her continuing Twitter tirade Sunday, Bynes lashed out at her detractors on Twitter and at her family.

"My real friends don't talk about me on twitter. Also, never trust or listen to a word any person from my family says to the press. I am suing them for money laundering/unethical manager work, I never signed a contract with them, and they had been stealing my money without me knowing … My parents are almost 70 years old. We are no longer on speaking terms. I would rather them be homeless than live off of my money," she wrote.

Bynes' parents did not respond to ABC News' requests for comment.

Bynes has displayed increasingly erratic behavior recently, leading many to question her mental health and publicly call for her to get help.

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