Source:
BBCCuban intelligence agents have deep involvement in Venezuela, according to a 2006 US diplomatic cable released by Wikileaks. Then-US Ambassador William Brownfield wrote that Cuban spies had "direct access" to President Hugo Chavez.
Another cable sent in 2010 said Cuban agents controlled spying operations against the US embassy in Caracas.
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The secret diplomatic cables released by Wikileaks were published by the Spanish newspaper, El Pais.
Similar allegations of Cuban intelligence influence in Venezuela have been made by Venezuelan opposition groups, but US officials have not publicly expressed such concerns.
The leaked cable from Ambassador Brownfield says the ties between Cuban and Venezuelan intelligence are so close that the two countries agencies "appear to be competing with each other for the Venezuelan government's attention".
Read more:
http://www.bbc.co.uk/news/world-latin-america-11883465
More synopsis at the link.
It appears that El Pais doesn't have an English edition, here's their article for any Spanish speakers:
http://www.elpais.com/articulo/internacional/espias/cubanos/actuan/libre/Venezuela/despachan/Chavez/elpepuint/20101130elpepuint_13/TesThe 2010 cable:
http://www.elpais.com/articulo/internacional/Cable/espionaje/cubano/dirige/operaciones/Venezuela/elpepuint/20101130elpepuint_39/TesThe 2006 cable:
http://www.elpais.com/articulo/internacional/Cable/servicios/inteligencia/cubanos/tienen/acceso/directo/Chavez/elpepuint/20101130elpepuint_36/Tes