Poet, playwright, short story writer, translator, and autobiographer James Kirkup (1918–2009) wrote under several pseudonyms in addition to his own name. The Wikipedia page for Kirkup lists "James Falconer, Aditya Jha, Jun Honda, Andrew James, Taeko Kawai, Felix Liston, Edward Raeburn, and Ivy B. Summerforest" as being among those pseudonyms. As far as I can tell, this list of pseudonyms was included at the time of the page's creation, though I could be reading the page history wrong. The citation given in Wikipedia for the list is to the James Kirkup papers in the Yale archives.
Yet the linked page at Yale describing the archive does not itself list Aditya Jha among Kirkup's pseudonyms. Instead, the "Additional Description" section includes this sentence: "Kirkup occasionally used pen names, including James Falconer, Jun Honda, Andrew James, Taeko Kawai, Felix Liston, Edward Raeburn, and Ivy B. Summerforest." The exact same list, except with no Aditya Jha. Nor does searching that archive for Aditya Jha yield any hits. By contrast, searching for the other names does bring up results associated with Kirkup.
The name Aditya Jha is also positioned oddly within the list of Kirkup's pseudonyms on the Wikipedia page: it is the only one out alphabetical order by last name. A Google search for "James Kirkup Aditya Jha" brings up several pages that repeat the list of pseudonyms in the same order as Wikipedia's, indicating that the ur-source for this claim is Wikipedia.
So: Did James Kirkup actually use the pen name Aditya Jha? If so, what works did he write using that name — poems, translations, essays, or something else? If not, it's probably futile to try to account for that name's appearance on his Wikipedia page, but editing the page might be the next step.