UK sheep meat imports for June dropped by 30% and those from Ireland dropped by 33%.
The AHDB (the organisation for English beef and sheep) reported that total imports to date fell by 18% for 2015 to 7,100t on the corresponding period last year.
This fall in UK imports has occurred despite the strength of the sterling, which has caused marketing difficulties for British lamb in continental Europe, it says.
The fall in imports are multi-factorial and have occurred as a result of high levels of domestic production and falling exports from New Zealand.
Sheep meat imports from Ireland fell by 33% for June despite the current strength of the Sterling in comparison to the euro.
New Zealand production increased in the recent months but June shipments from New Zealand have fallen 16% to 5,200t on the same period in 2014.
Total New Zealand imports to the UK remain at similar levels to 2014 but imports from April to June have fallen by 19%, despite imports being up by 23% for the first three months of the year, it says.
Imports of sheep meat from Australia have also fallen by 8% which leaves overall sheep meat imports to the UK for the first half of the year down 4% on 2014 levels to 56,600t, says the AHDB.
UK sheep meat exports for June are also down by 30% due to the strength of the Sterling which has reduced the competitiveness of UK exports to Europe, it says.
The disruption in the French port of Calais has also been cited as a contributing factor to the reduced exports of UK lamb.
France currently accounts for 50% of total UK lamb exports but June exports are down 13% to 3,700t.
Exports to Ireland and Belgium are down by 40%, it says, but exports to Germany have increased by 33%.
It also reports that the levels exported to Hong Kong are down significantly as the trade situation in that region remains difficult.