FORT LAUDERDALE, Florida (REUTERS) - A Chinese woman arrested by the Secret Service after she snuck into President Donald Trump's Florida resort aroused the suspicions of staff by filming and behaving oddly, witnesses at her trial said on Tuesday (Sept 10).

The actions of Yujing Zhang, 33, at Trump's Mar-a-Lago private club in March sparked concerns that she was potentially a spy although she was charged only with trespassing and making false statements.

In the second day of the trial in US District Court, Ariela Grumaz, a front desk receptionist, told the jury that Zhang "was acting very weird and strange" at the Palm Beach resort on March 30.

The Chinese national ignored a "no filming" sign and, using her cell phone, captured video of the ornate lobby as she strolled inside, raising suspicions and prompting Grumaz to urge security personnel to watch her.

Wearing an evening dress in the early afternoon, Zhang began texting on her cell phone, and Grumaz asked her to leave. Zhang calmly walked outside and was immediately surrounded by Secret Service agents.

"That is what struck me. She was totally in control," Grumaz testified.

Zhang has taken an unusual approach in choosing to serve as her own lawyer and at times has expressed confusion about the proceedings.

"I don't even know why I'm here today. I thought my case was canceled," Zhang told the judge on Monday.

The judge has urged her to accept a public defender but allowed the trial to proceed. Zhang faces up to six years in prison if convicted.

At the time of her arrest, Zhang had four cellphones, a laptop computer, an external hard drive device and a thumb drive, the Secret Service said in a court filing. Initial examination of the thumb drive determined it contained"malicious malware," the Secret Service said.

After the trove of electronics was found on Zhang, a search of her Palm Beach hotel room reportedly uncovered a device meant to detect hidden cameras and nearly US$8,000 (S$11,000) in cash.

Questioned by US District Judge Roy Altman as to the purpose of calling Grumaz as a witness, Assistant US Attorney Michael Sherwin said her testimony was aimed at showing Zhang was not a wandering tourist but rather on a "mission" to get on the Trump property.

Trump visited Mar-a-Lago the weekend Zhang was arrested, but he was playing golf during her time at the property.

Prosecutors said they expect the trial to end on Wednesday.