Filter results to only display one node from each author

We need to create a block which displays the most recent three nodes from a content type, but limits the results to only show one result per author. We can't find any way of doing this with standard filters.

For example, if we have the following nodes;

NID 6 - Author ID 3
NID 5 - Author ID 3
NID 4 - Author ID 3
NID 3 - Author ID 2
NID 2 - Author ID 1
NID 1 - Author ID 1

The view would display;

NID 6 - Author ID 3
NID 3 - Author ID 2
NID 2 - Author ID 1

Any help would be appreciated!

Thanks,
Adam