The team leader could be informed of this through an anonymous letter perhaps.
Step-by-step explanation:
Any team leader who is polite and understanding with their team while getting the job done is usually an asset to the team.
however, too much leeway would also mean that the workers become alx and do not listen to their leaders.
In this case this is happening indirectly because the clerks enjoy talking to their leader and use up their working hours doing that.
Working hours are precious for the firm and this actually decreases the productivity.
The team leader can simply be informed anonymously that members have noticed this happening and want her to correct it.