When Imhotep Institute Charter High School opened its new building in East Germantown five years ago, officials dubbed the $10 million facility "the Miracle on 21st Street."

Now, as the school with an African-centered curriculum fights to keep its charter, the building at 6201 N. 21st St. is at the center of a tug-of-war.

Sankofa Network Inc., a related nonprofit that owns Imhotep's campus, filed a Common Pleas Court lawsuit last week alleging the charter owes $1.2 million in rent, interest, and fees.

The court action comes after the school, which opened in 1998, was rocked by months of turmoil, including the ouster in late June of M. Christine Wiggins, Imhotep's founding chief executive.

The Imhotep board voted not to renew Wiggins' contract after the School District's charter office said in April that it would recommend not renewing the school's charter on several grounds, including poor academic performance.

Supporters of Wiggins, who have created an online petition at MoveOn.org to "Save Imhotep Institute Charter High School," have said her removal was the work of a "rogue board."

Wiggins, who is known as "Mama Chris," could not be reached for comment Tuesday.

George Gossett, Imhotep's lawyer, called the suit "frivolous." He said the building's future is not in jeopardy and the charter's finances were sound.

"It is not a correct lawsuit," Gossett said. "They are saying that the rent had not been paid. That is not correct. The rent is paid directly to the bank that has the mortgage on the property."

He said members of Sankofa's board are relatives of or have close ties to Wiggins.

"We believe that some of the actions are retaliatory in nature because [Wiggins'] contract was not renewed," Gossett said.

Tameka Thomas-Bowman, the president of Sankofa's board who signed off on the suit, is a daughter of Wiggins and a former Imhotep employee.

Sharon Wilson, a lawyer who represents Sankofa Network, said the nonprofit acted after it was told by the bank that as of Oct. 1 it was delinquent nearly $900,000 in repaying a construction loan and a line of credit.

The complaint, Wilson said, is an attempt to sort out the finances amid changing board members and administrative turnover at Imhotep.

As is often the case with charters in Pennsylvania, Imhotep created a nonprofit that obtained the mortgage and owns the building the school leases. It is often easier for a related nonprofit to obtain long-term financing than a charter, which is subject to renewal every five years.

Wilson said the complaint Sankofa filed last week, technically a "confession of judgment," was the best and fastest way to obtain an exact accounting of what the school has paid and when.

She said in the past that Imhotep and Sankofa "had less formality than was probably good for either of them."

Concerns about academic performance at Imhotep prompted the district's charter office to express reservations about renewing the school's charter.

Although Imhotep, which has 525 students in grades nine through 12, has been praised for sending a high percentage of its graduates to college, the school's records show that in 2013, only 9 percent of Imhotep students scored proficient on the state's Keystone exams in Algebra 1 and 5 percent in Biology 1. In literature, 37 percent were proficient.

The school is known as a local football powerhouse that also has strong basketball programs.

District spokesman Fernando Gallard said that in addition to academic concerns, the district has been awaiting results of investigations by the state Department of Education and Imhotep itself on irregularities on state PSSA tests.

"The [charter] renewal has been delayed, pending the outcome of the investigation of test irregularities," he said.

Imhotep was among several charter and district schools where examiners flagged erasure patterns and changed answers on standardized tests as part of a statewide cheating investigation.

Gallard said the district wanted to be able to review Imhotep's scores from 2012-13 and 2013-14 because its scores dropped "significantly" after the state instituted strict new testing procedures in 2012.

"As we do with every charter renewal, we are also going to be looking at the audit of the financials of the school, which goes directly to the question in regards to the current dispute between the school and the foundation," Gallard said.

He said that the School Reform Commission is expected to vote on Imhotep's renewal this academic year.