A source confirms the custody dispute will need to be handled in court if attorneys for Tomlinson, 24, and Briana Jungwirth, the baby's mother, are unable to reach a long-term custody and child support agreement. For now, though, the insider says the parents have "an interim agreement in terms of access" that will remain in effect for a matter of weeks. Although overnight visits are not on the table, several hours of visitation per week are part of the temporary plan.
Jungwirth – a Los Angeles-based stylist whom Tomlinson briefly dated last May – allegedly denied the pop star access to their 5-week-old son over a disagreement about Tomlinson's financial contributions, TMZ reports.
A source tells PEOPLE that Tomlinson covered Jungwirth's expenses and was working on a fixed financial agreement with her. However, the negotiations stalled when she requested more than he deemed reasonable. (Sources close to both parents tell PEOPLE Tomlinson is extremely generous financially.)
Jungwirth gave birth to Freddie on Jan. 21, six months after PEOPLE confirmed she was expecting.
"It was a surprise at first, but he and Briana are very, very close friends and this has brought them even closer," a mutual friend of the parents told PEOPLE at the time.
In the midst of the pregnancy, Tomlinson moved on with new girlfriend Danielle Campbell, 21, an actress on CW's The Originals. The duo were most recently spotted showing PDA while grocery shopping in L.A. this month, but the "Perfect" singer appeared at the Brit Awards in London without her Wednesday.
A rep for Tomlinson declined comment.