ActiveMQ resource adapter opens connections but never closes them

Issue

We have an application inside JBoss EAP and talks to a Fuse MQ Enterprise 7.0.1, both on Solaris. It opens connections to Fuse MQ for 9 different JMS queues. This works fine and data can be processed. However, it opens connections but never closes them. Every 2 minutes it opens new connections. So we are getting more and more connections/threads on the server and it causes big trouble on a production system.