Getting many warnings "duplicate message ... from cursor, is cursor audit disabled or too constrained? Redirecting to dlq"

Issue

Under broker load we are seeing many warnings of this kind

[2017-03-21 09:51:37,548] WARN ActiveMQ BrokerService[localhost] Task-5 Queue - queue://TEST, subscriptions=10, memory=102%, size=399, 
pending=0, duplicate message ActiveMQTextMessage {commandId = 72, responseRequired = true, 
messageId = ID:Mac.fritz.box-64479-1490086286066-183:1:1:1:68, originalDestination = null, originalTransactionId = null, 
producerId = ID:Mac.fritz.box-64479-1490086286066-183:1:1:1, destination = queue://TEST, transactionId = null, expiration = 0, 
timestamp = 1490086297427, arrival = 0, brokerInTime = 1490086297427, brokerOutTime = 1490086297427, correlationId = null, replyTo = null, persistent = true, 
type = null, priority = 4, groupID = null, groupSequence = 0, targetConsumerId = null, compressed = false, userID = null, 
content = org.apache.activemq.util.ByteSequence@8672edc, marshalledProperties = null, dataStructure = null, redeliveryCounter = 0, size = 50216, properties = null, 
readOnlyProperties = false, readOnlyBody = false, droppable = false, jmsXGroupFirstForConsumer = false, text = ...XXXXXXXXXXXX} 
from cursor, is cursor audit disabled or too constrained? Redirecting to dlq

What is causing these warnings and what does it mean for our messages?