(Reuters) - The Baltimore City Council on Monday called on Mayor Catherine Pugh to resign as the state probes a deal in which a hospital chain where she served as director paid her $500,000 for copies of her self-published children’s book “Healthy Holly.”

Pugh, a 69-year-old Democrat first elected in 2016, last week said she would take an indefinite leave of absence for health reasons after the Baltimore Sun revealed the deal with the University of Maryland Medical System.

“The entire membership of the Baltimore City Council believes that it is not in the best interest of the city of Baltimore for you to continue to serve as mayor,” the council wrote to Pugh in a letter signed by 14 members. “We urge you to tender your resignation, effective immediately.”

Every member of the council signed the letter except Bernard “Jack” Young, the council president who is currently serving as acting mayor of the city. He was also sent a copy of the letter.

Pugh’s office on Monday released a statement saying her leave of absence was solely related to her health. “She fully intends to resume the duties of her office and continue her work on behalf of the people and the City of Baltimore,” the statement read.

Pugh was serving on the board of the University of Maryland Medical System when she received payments for the books from 2012 through 2018. She was among nine members of the board with some form of business arrangement with the medical system, the newspaper reported. She is no longer on the board.

The “Healthy Holly” series promotes healthy choices for children, such as exercise and eating vegetables.

Maryland Governor Larry Hogan, a Republican, last week asked the state prosecutor to investigate the University of Maryland Medical System payments to the mayor.

Pugh has apologized for the book sales to the university and called the arrangement “a regrettable mistake.”

She said in a statement last week that she has been battling pneumonia for a few weeks and her physicians have advised her to focus on recuperating.

City Councilman Eric Costello said on Monday he was “deeply concerned” about the toll the scandal has taken on the city.

“The myriad of investigations underway into the various business dealings involving the mayor raises significant ethical and legal issues,” Costello said on Twitter. “It will be impossible for Mayor Pugh to govern effectively.”